Aer Lingus is to transfer its operations to the new Terminal 2 at Dublin Airport.
The airline says the move to the new terminal, which will open for business in November, will allow it to operate more efficiently for customers, without any significant increase in the groups operating costs.
In addition to the relocation Aer Lingus says its also agreed to work with the Dublin Airport Authority to boost transfer and other traffic at Dublin airport, and to develop "new and innovative customer products and services".
The DAA earlier this week announced the immediate recruitment of 500 new staff to work at the terminal.